1 // Copyright 2015 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef BASE_I18N_MESSAGE_FORMATTER_H_ 6 #define BASE_I18N_MESSAGE_FORMATTER_H_ 7 8 #include <stdint.h> 9 10 #include <memory> 11 #include <string> 12 13 #include "base/i18n/base_i18n_export.h" 14 #include "base/macros.h" 15 #include "base/strings/string16.h" 16 #include "base/strings/string_piece.h" 17 #include "third_party/icu/source/common/unicode/uversion.h" 18 19 U_NAMESPACE_BEGIN 20 class Formattable; 21 U_NAMESPACE_END 22 23 namespace base { 24 25 class Time; 26 27 namespace i18n { 28 29 class MessageFormatter; 30 31 namespace internal { 32 33 class BASE_I18N_EXPORT MessageArg { 34 public: 35 MessageArg(const char* s); 36 MessageArg(StringPiece s); 37 MessageArg(const std::string& s); 38 MessageArg(const string16& s); 39 MessageArg(int i); 40 MessageArg(int64_t i); 41 MessageArg(double d); 42 MessageArg(const Time& t); 43 ~MessageArg(); 44 45 private: 46 friend class base::i18n::MessageFormatter; 47 MessageArg(); 48 // Tests if this argument has a value, and if so increments *count. 49 bool has_value(int* count) const; 50 std::unique_ptr<icu::Formattable> formattable; 51 DISALLOW_COPY_AND_ASSIGN(MessageArg); 52 }; 53 54 } // namespace internal 55 56 // Message Formatter with the ICU message format syntax support. 57 // It can format strings (UTF-8 and UTF-16), numbers and base::Time with 58 // plural, gender and other 'selectors' support. This is handy if you 59 // have multiple parameters of differnt types and some of them require 60 // plural or gender/selector support. 61 // 62 // To use this API for locale-sensitive formatting, retrieve a 'message 63 // template' in the ICU message format from a message bundle (e.g. with 64 // l10n_util::GetStringUTF16()) and pass it to FormatWith{Named,Numbered}Args. 65 // 66 // MessageFormat specs: 67 // http://icu-project.org/apiref/icu4j/com/ibm/icu/text/MessageFormat.html 68 // http://icu-project.org/apiref/icu4c/classicu_1_1DecimalFormat.html#details 69 // Examples: 70 // http://userguide.icu-project.org/formatparse/messages 71 // message_formatter_unittest.cc 72 // go/plurals inside Google. 73 // TODO(jshin): Document this API in md format docs. 74 // Caveat: 75 // When plural/select/gender is used along with other format specifiers such 76 // as date or number, plural/select/gender should be at the top level. It's 77 // not an ICU restriction but a constraint imposed by Google's translation 78 // infrastructure. Message A does not work. It must be revised to Message B. 79 // 80 // A. 81 // Rated <ph name="RATING">{0, number,0.0}<ex>3.2</ex></ph> 82 // by {1, plural, =1{a user} other{# users}} 83 // 84 // B. 85 // {1, plural, 86 // =1{Rated <ph name="RATING">{0, number,0.0}<ex>3.2</ex></ph> 87 // by a user.} 88 // other{Rated <ph name="RATING">{0, number,0.0}<ex>3.2</ex></ph> 89 // by # users.}} 90 91 class BASE_I18N_EXPORT MessageFormatter { 92 public: 93 static string16 FormatWithNamedArgs( 94 StringPiece16 msg, 95 StringPiece name0 = StringPiece(), 96 const internal::MessageArg& arg0 = internal::MessageArg(), 97 StringPiece name1 = StringPiece(), 98 const internal::MessageArg& arg1 = internal::MessageArg(), 99 StringPiece name2 = StringPiece(), 100 const internal::MessageArg& arg2 = internal::MessageArg(), 101 StringPiece name3 = StringPiece(), 102 const internal::MessageArg& arg3 = internal::MessageArg(), 103 StringPiece name4 = StringPiece(), 104 const internal::MessageArg& arg4 = internal::MessageArg(), 105 StringPiece name5 = StringPiece(), 106 const internal::MessageArg& arg5 = internal::MessageArg(), 107 StringPiece name6 = StringPiece(), 108 const internal::MessageArg& arg6 = internal::MessageArg()); 109 110 static string16 FormatWithNumberedArgs( 111 StringPiece16 msg, 112 const internal::MessageArg& arg0 = internal::MessageArg(), 113 const internal::MessageArg& arg1 = internal::MessageArg(), 114 const internal::MessageArg& arg2 = internal::MessageArg(), 115 const internal::MessageArg& arg3 = internal::MessageArg(), 116 const internal::MessageArg& arg4 = internal::MessageArg(), 117 const internal::MessageArg& arg5 = internal::MessageArg(), 118 const internal::MessageArg& arg6 = internal::MessageArg()); 119 120 private: 121 MessageFormatter() = delete; 122 DISALLOW_COPY_AND_ASSIGN(MessageFormatter); 123 }; 124 125 } // namespace i18n 126 } // namespace base 127 128 #endif // BASE_I18N_MESSAGE_FORMATTER_H_ 129